Helical cutter for textile fibers



June 29, 1965 ISAMU KlKUCHl j 3,191,479

HELICAL CUTTER FOR TEXTILE FIBERS Filed July 2, 1962 FIG-*1 INVENTOR.

ISA MU KIKUC HI. BY

fi/Mk 1:70am EY United States Patent 3,191,479 HELICAL CUTTER FOR TEXTILE FIBERS Isamu Kikuchi, Kosakai-cho, Hui-gun, Aichi-ken, Japan, assignor to Fuji Spinning Co., Ltd. Filed July 2, 1962, Ser. No. 206,857 7 Claims. (Cl. 83-672) This invention relates to helical-type cutters and, more particularly, to cutters of the aforesaid type for cutting tow for spinning.

In spinning stable fiber it is customary to use tow that has been cut into fibers of a fixed length, say, four inches. This has the disadvantage that is likely to cause irregularities in the twist because when the forward ends of the fibers are coincident the rearward ends thereof also coincide with the result that the number of fibers in the formation decreases as drafting is repeated.

It is therefore chiefobject of the invention to provide a helical-type cutter which eliminates or obviates the aforesaid disadvantages and drawbacks.

As a corollary, it is an object of the invention to provide a cutter of the type aforesaid, wherein the cut fibers have lengths which vary between predetermined minimum and maximum values, while having a fixed predetermined average length.

Another object is to afford a system wherein the aforesaid average length may be selected as desired, as well as the aforesaid minimum and maximum lengths of individual fibers, and the corresponding helix angles of standard and variable blades selected to give the desired average, minimum and maximum lengths.

Other objects and advantages Will become apparent to those skilled in the art after a study of the following detailed description, in connection with the accompanying drawing. a

In the drawings:

FIG. 1 is a side elevation of a helical-type cutter embodying the invention;

FIG. 2 is a sectional view to a greatly enlarged scale, of a portion of the cutter taken in a plane through its longitudinal axis;

FIG. 3 is a diagrammatic view showing the manner in which the helix angles of the respective blades are computed; I

FIG. 4 is a diagrammatic view looking from one end of the cutter and showing the circumferential spacing of the two standard and the two variable blades;

FIG. 5 is a view corresponding to FIG. 4, and showing the equal spacing of all blades in a cross section midway between the ends of the cutter; and

FIG. 6 is a view corresponding to FIG. 4 and showing the circumferential spacing of the blades at the opposite end of the cutter as measured in the same direction of rotation about the cutter as in FIG. 4.

Referring in detail to the drawing, 1 identifies a helical type cutter having four blades. Reference numeral 2 identifies blades which are set at a standard or conventional angle assumed for the purpose of illustration to have a lead of 2 inches, while 3 represent blades having a lead different from blades 2, computed in a manner sub sequently described. As more fully illustrated in FIG. 2, the cutter may comprise a steel body formed with helical threads defining the cutter blades 2 and 3 and with the space between blades provided with the usual rubber filling 4.

In the following description and in the claims, the blades 2 and 3 will be identified as standard and variable, respectively.

As an example of the manner in which the helix angles 3,191,479 Patented June 29, 1965 'ice of the standard and variable blades may be computed, the following constants are assumed:

Thus the average length of cut fibers is 15.7/4=3.93" or approximately 4"; and the distance measured circumferentially between the two standard blades, is

2 .3.93"=7.85 which may be conveniently divided into 3.45" and 4.40" to give a range of lengths closely approximating that desired.

Consider a development of the circumscribing cylinder about the cutting edges of the blades, as a rectangle having a vertical dimension of 12 /2" and horizontal upper and lower edges. Measure 15.7" along the lower edge of this rectangle, from a first point A at the lower left corner thereof, and erect a perpendicular at the second point B, so determined. Determine a third point C on this perpendicular 2" from the lower end thereof, corresponding to the assumed 2" lead of the standard blades, and draw a straight line AC. Then this line represents the development of a standard blade and its helix angle 0, is arctan 2/ 1 5 .7=7=1524.

' Assume the aforesaid rectangle to extend indefinitely to the right and the straight line AC just drawn to be also extended until it intersects the top edge of the rectangle extended, to determine a fourth point D. Drop a perpendicular from point D to intersect the lower edge of therectangle at point B. Next measure the distance of 4.4" to the right from point A, along the lower edge of the rectangle to determine point F, and a distance 3.45" to the right from point D, along the upper edge of the rectangle, to determine a point G. Drop a perpendicular from point G to intersect the lower edge of the rectangle at point I. Then a line FG represents a development of the variable blade satisfying the assumed relations and which intersects the line BC at a point H.

Then, by simple triangles, the distance AE=98.125", the helix angle 6 of the variable blade is 12.5 98.125 (4.43.45) and the lead of the variable blades is or, in general terms, where L and D are the axial dimension and effective diameter of the cutter, respectively: I is the aforesaid distance AB; 1 the distance FI; x the lead of the standard blades, a and b the reciprocably variable circumferential distances from one standard blade to the next variable blade, and from the variable blade to the next standard blade, such that a+b=the constant circumferential distance between the two standard blades:

Since the cutter has alternate blades set at a helix angle somewhat larger than the corresponding angle of the standard blades, the range of fiber lengths can be varied within a certain range by varying the helix angle of the variable blades, 1 being always less than I The invention therefore eliminates the drawbacks inherent in a helical-type cutter having all blades set at the same helix angle, and also has other advantages such as enabling the production of varied staple patterns based on use or purpose and particular tastes of the designer.

It should be understood that the foregoing disclosure arctan 19' 34 3 relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and the scope of the invention set forth in the appended claims.

Having now fully disclosed the invention, what I claim and desire to secure by Letters Patent is:

1. In a helical blade cutter, a cylindrical body having first and second non-intersecting blades fixed to and extending helically about the cylindrical surface of said body, said blades having different helix angles and extending in the same direction of rotation about said cylindrical body.

Z. A helical blade cutter comprising a cylindrical body, a standard blade extending helically about the cylindrical surface of said body in fixed relation therewith and having a predetermined lead, a variable blade extending helically about said body in fixed relation therewith and in non-intersecting relation with said standard blade, the termini ofsaid blades at one end of said body being circumferentially spaced by a distance a, the termini of said blades at the other end of said body being circumferentially spaced by a distance b, where a and b are dissimilar linear dimensions and are measured from respective ends of said standard blade, in the same direction about said body.

3. A helical blade cutter comprising a cylindrical body, a first pair of standard blades extending in diametrically opposed relation at a first helix angle about said body, and a second pair of variable blades extending in diamet rically opposed relation at a second helix angle about said body, said second helix angle being greater than said first helix angle, said first and second blades being non-intersecting said standard and variable blades being alternately disposed and extending in the same direction of rotation on and about the cylindrical surface of said body.

4. A helical blade cutter as in claim 3, the helix angle of said first pair of blades being arctan x/arD, where x is the lead thereof and D is the effective diameter of the cutter blades, each blade of said second pair being so disposed that the circumferential spacings thereof at the respective ends of said body, from and between the blades of said first pair, are a, b and b, a, a and b being unlike linear values and measured in the same direction of rotation about said body. a

5. A helical blade cutter of the type described comprising a cylindrical body, having a first plurality of blades extending helically thereabout at a first preselected helix angle, and a second plurality of blades extending helically thereabout at a second preselected helix angle greater than said first angle, each blade of said second plurality being positioned in a respective space between a successive pair of blades of said first plurality, all said blades being fixed with said body, each said blade of said second plurality having a circumferential spacing at one end of said body, from and betwen a successive pair of blades of said first plurality, of preselected distances a and b, and a circumferential spacing at the other end of said body, from and between said successive pair of blades of said first plurality, of b and a measured in the same direction about said body, a and b being dissimilar linear values, all said blades being discrete and non-intersecting.

6. A helical blade cutter comprising a cylindrical body having an axial dimension of 12 /2" and a diameter of 5", a first pair of diameterically-opposed standard blades extending helically about said body with a lead of 2" and a helix angle of 7 15 24", and a second pair of variable diametrically-opposed blades extending helically about said body, each blade of said second pair lying in a respective one of the spaces between said first pair of blades, the circumferential spacings between each blade of said second pair and the bladesof said first pair, at one end of said body, being 3.45" and 4.40" and the corresponding circumferential spacings between each blade of said second pair and the blades of said first pair, at the other end of said body being 4.40"'and 3.45", all said spacings being measured in the same direction of rotation about said body.

'7. In a helical blade cutter, a cylindrical body having first and second non-intersecting blades fixed to and extending helically in the same direction of rotation about the cylindrical surface of said body, each said blade extending at least a complete turn about said body, the helix angles of said blades being materially different one from the other.

References Cited by the Examiner UNITED STATES PATENTS 955,776 4/10 Dyson 83-342 2,183,722 12/39v Newman s3 342 2,221,716 11/40 Morton 83-672 2,224,668 12 40 Christian s3 -342 FOREIGN PATENTS 183,667 4/07 Germany.

742,815 12/43 Germany.

ANDREW R. JUHASZ, Primary Examiner, 

1. IN A HELICAL BLADE CUTTER, A CYLINDRICAL BODY HAVING FIRST AND SECOND NON-INTERSECTING BLADES FIXED TO AND EXTENDING HELICALLY ABOUT THE CYLINDRICAL SURFACE OF SAID BODY, SAID BLADES HAVING DIFFERENT HELIX ANGLES AND EXTENDING IN THE SAME DIRECTION OF ROTATION ABOUT SAID CYLINDRICAL BODY. 